This was answered on here not long ago and the conclusion was no for that very reason.
There is no legitimate reason to listen to the police frequencies - they are all digital and cannot be decrypted for very good reasons. Gone are the days you can listen to where the Fire Brigade was going as they past your door by tuning into the top end of the FM Band.
yep, they've gone from analogue to digital (well, my county has anyway and i'm pretty certain the whole country has) and they are 'unscannable'. the kit they use now is like a mobile phone and, as of last year, they knew of no way/of no existing equipment that could intercept the frequncy..... and because of this, apparently there is a high price on their handsets!